Implantable medical devices can be used for monitoring (e.g., ongoing glucose monitoring) and for stimulation (e.g., to regulate the beating of a heart). An example device can include an electronics package connected to one or more leads via a connector. The one or more leads can be placed at a target location for monitoring or stimulation. In a monitoring scenario, the leads gather information from the target location and the electronics package processes the information. In a stimulation scenario, the electronics package generates electrical signals that are delivered to the target location via the leads.